Crane



Sept. 2l, 1954 K. F. POTTER ETAL CRANE 5 Sheets-Sheet 1 Filed Nov. l, 1951 Sept. 2l, 1954 Filed NOV. l 1951 K- F. POTTER ET AL CRANE 5 Sheets-Sheet 2 @MM Q/n/w A Tram/vf; v5

Sept. 21, 1954 K. F. POTTER ETAL CRANE 5 Sheets-Sheet 3 Filed Nov. l 1951 D Tm M m@ M 0.5555 in@ MQW N n ur. D W W KAmA Sept. 2l, 1954 Filed Nov. l 1951 K. F. POTTER ET AL CRANE 5 Sheets-Sheet 4 Kam/gm LT DUTTQ: Aaa/ ACQ W. [550W/v f/v V/:A/ TUQS l Tram/Vg v5 SePt- 21 1954 K. F. POTTER ET AL 2,689,655

CRANE 5 Sheets-Sheet 5 Filed NOV. l 1951 Patented Sept. 21, 1954 CRANE..

Kenneth F. Potter, St. Paul, and Archer. W. Brown, Minneapolis, Minn., assignors to American Host &'Derrick Co., corporation of- Delaware St. Paul, Minn., a

Application November 1, 19.51,.Serial No. 254,356

2 Claims. li

The invention` herein has relation to a crane or like machine4 ofthe character adapted to travel over theA ground; andequipped'with mechanism for hoisting; swinging.and/orexcavating, etc.

r The purpose of the invention is to provide a crane, or like machine, wherein will be incorporated a new and improved construction and arrangementl including a collapsible mast adapted to be lowered when lowering ofthe collapsible mastis` necessary or desirable, and also includ'- ing novel and improved mechanism for removing and replacing a counterweight ofthe crane.

In the accompanying drawings forming a part Off' this specification,

Fig.' 1` is-a'side elevational'viewof a crane made according to the invention;

Fig. 2 is a sideelevationalview,v on a reduced scale, disclosing a mast off the crane of Fig. 1 in collapsedposition; and a counterweight of said crane aswhen restedupon'the ground;

Fig. 3 is1a-view corresponding generallyl with the disclosure of Fig. 2; showing a boom of the cranelowered intoa cradle thereof;

Fig. 4 isla view corresponding generally with the disclosure of Fig. 3, showing struts of said crane detachedi from the; counterweight and securedito a rotatable platform of the crane;

Fig. 5 isla View,` corresponding generally with the disclosure of Figs. 2 to 4, showing parts-of the crane:` situated as'when thecounterweight is beingl conveyed; asto a truck said counterweight;

Fig.: 6 is;` a view corresponding generally with the:disclosurefofi` Figs. 4iand5, showing the crane as, when parts.c thereof'v areV moved or adjusted from positions as in-Lsaidr Eig: 5 topositions about as inrsaidrFig. 4;

Fig. 7! is;an: enlarged side-elevational view detailing a unit ofy the:crane'includingritsmast and struts asparts thereof, andalso. including spaced barsof: an inner bail assembly ofthe crane;4

Fig. 8 is anzenlarged side' elevationallview of a strut of the yunitdisclosed inFi'g. 7i;

f Fig. 9 isa detail sectional view,ltaken online 9 9 in Fig. 81;

Fig. l0..- is ani enlarged plan View` off the unit disclosed: in` Fig. 7 additionally' showing elements of the. crane assembled with` sa-idl unit, as` said unit and elements would appear from position above` the disclosure inFig. 1;

Fig. 11 is a` fragmentary plan View showing parts. of the unitl and elements disclosed in Fig. in different positions; andj Fig. 12'` is, an end' elevational view, partially broken away, of the crane as it would appear fromthe right in Fig. 1.

for transportingV tor.

Said truck or equivalent I5 supports a platform I8- which is rotatable upon the truck in a customary or preferred way also forming no part of the invention. The'rotatable platform I8 constitutes theiioor or a cab I9 of the crane;

A boom 20, of ordinary construction as disclosed, is pivotally supported, as at 2|, upon the rotatable platform I 8'for rotative movement in a- Vertical plane. The cab Isupports a unit consisting of a collapsible mast 22, a pair ofspacedstruts 23` and a` pair of spacedbars 24' constituted as a part of an inner bail assembly of the crane.

Spaced apart, longitudinally extending frame membersof the collapsible mast 22 are represented 25, and-spacedapart, transversely extending. frame members of said mast are indicated 2.6. The longitudinalframe members 25`and` the transverse frame members 26` are interconnected toV provide a rectilinear structure or frame `which isreinforcedrby oblique and transversestrengthening members. The longitudinal and transverse frame members and theoblique and transverse strengthening membersare welded, or otherwise secured; into an integral construction.

The inner orlower end of the collapsible mast 22 includes spaced apart,.integral arms 2T eX- tending away fromsaidinner or lower end of the frame of said mast and alined with' thei longitudinal frame members 25 thereof. The cab I9 includes spaced apart, upstanding arms 28 integral with. upper portions of theside walls of lsaid cab. The arms 21 and 28` include overlapping parts thereof in a vertical plane'passed transversely through the cab I9 parallel` to the axis 2I for the boom, and` said arms 2 and` 28 are situated at the side of the boom axis opposite the boom, rearwardly of said. boom, in consider.- ably spaced relation tothe boom axis as disfclosed.

A transverse shaft 29 having its opposite end portions mountedin openingsthrough said overlapping portions of the arms 2 and 28 consti.- tutes means pivotally supporting the4 collapsible mast 22 upon the cab I9 ofthe crane. Said mast extends rearwardly of the cab from the axis 29 and is disposed obliquely upwardly, as in Fig. 1, when in use and horizontally, as in Figs. 2 to 6, when collapsed. The transverse shaft 29 supports a sheave 35 for a purpose to be set forth.

A transverse shaft 3|, situated in spaced relation to the transverse shaft 29, has its opposite end portions mounted in outer or upper extremities 32 of the longitudinal frame members 25, at the rear of the rear transverse frame member 26, and the transverse shaft 3| rotatably supports the spaced struts 23, which extend downwardly from said transverse shaft, and the spaced bars 24, which extend forwardly from the transverse shaft.

Short cables 33, at each side of the boom 29, have their outer ends secured, as at 34, to the boom point. The inner ends of the short cables 33 are suitably and conveniently secured, as at 35, to spaced apart, longitudinal plate members 36 adjacent each side of the crane. A transverse shaft 31 in each set of spaced apart, longitudinal plate members 36 rotatably supports a sheave 38.

Spaced apart, transverse plate members 39, ex-

tending between and secured to the spaced apart,

longitudinal plate members 36, rotatably support transversely spaced sheaves 40.

The ends of the spaced bars 24 of the inner bail assembly opposite or spaced from the transverse shaft 3| are pivotally connected, by a cross pin 4|, with spaced ears 42 rigid with spaced transverse plate members 43 and extending longitudinally of the crane, and the spaced transverse plate members 43 rotatably support transversely spaced sheaves 44.

The rotatable platform I8 suitably and conveniently supports a power plant (not shown) for operating a rotatable drum 45 for manipulating the boom 2li. A cable 46 for the purpose of accomplishing raising and lowering operations of said boom has one of its ends secured to the drum 45. From said drum the cable 46 passes over the sheave 30 on the transverse shaft 29 and is reaved suitably and properly over all of the sheaves 33, 4U and 44. The end of said cable 46 opposite or spaced from the drum `45 is secured, as at 41, to a part of the transverse shaft 29 spaced from the sheave 30.

The power plant also operates a rotatable drum 48 for manipulating a hoisting hook 49, or other member substituted for said hoisting hook to the accomplishment of the like or a different purpose. A cable 50 for the hoisting hook has its inner end attached to the drum 48 and leads from said drum over a. sheave upon the outer end of the boom to said hoisting hook.

The rotatable drums 45 and 48 of course will be under the control of brakes, etc., usually employed in machines of the present general character.

A counterweight 52 of or for the crane is detachably secured, as by bolts 53, to a rearward part of the revolvable platform I8, or part of said revolvable platform directly opposite the pivotal support 2| for the boom 20.

Each of the spaced struts 23 is constituted as an upper and a lower telescopic rod, denoted 54 and 55, respectively. The upper end of each upper telescopic rod 54 is the part of the corresponding strut which is rotatably supported upon the transverse shaft 3 and the lower end of each lower telescopic rod 55 is detachably secured, as at 56, to the counterweight 52. Means for limiting the extent to which the lower telescopic rods 55 can be moved longitudinally in direction away from the upper telescopic rods 54 of the struts 23 are constituted as cap members 51 rigid with the lower ends of the upper telescopic rods 54 to be engaged by collar members 58 rigid with intermediate portions of the lower telescopic rods 55. f i

When the lower ends of the lower telescopic rods 55 of the struts 23 are secured to the counterweight 52, the collapsible mast 22 will be at xed oblique position or elevation, as in Figs. 1 and 12 of the drawings. It will be evident that rotation of the drum 45 in one direction, while the mast is situated as in said Figs. 1 and 12, will cause the boom to be raised by shortening of the cable 46, and that rotation of said drum in opposite direction will permit said boom to be lowered by gravity by reason of lengthening of said cable.

Numeral 59 represents ordinary outriggers with Outrigger beams 69. In Fig. 12 Outrigger beams are disclosed as when partially withdrawn from rear outriggers by which contained.

In some instances when cranes having high masts, as in Figs. 1 and 12 of the drawings, are employed to the accomplishment of their intended purposes,l overhead clearances beneath which the cranes are required to travel are too 10W to allow passage of their high masts. On erection work, for instance, long booms are ordinarily preferable and sometimes necessary, and when a long boom is employed it is quite desirable that a high mast be utilized, both to the purpose that the mast will be at more advantageous lifting relation with respect to the boom and that the tension of the boom suspension will be reduced. At the same time, cranes useful for erection work usually have overall height too great to be shipped or transported with their masts applied. When overhead clearances are to be passed, the masts of the cranes must either be detached or collapsed. In the disclosure as made, the mast 22 is collapsible.

The counterweight 52 is for the advantageous purpose of balancing the boom 20 and its load, and said counterweight is removable to the end that the overall weight of the crane can be reduced when it is transported, either under its own power, or the power of a conveying vehicle for the crane.

In Fig. 1 of the drawings, the weight of the boom 20 is suspended from the collapsible mast 22 by the cables 33, the spaced a part bars 24, the connection between said cables. 33 and spaced bars 24, and the struts 23 in such manner that there is tendency toward. swinging said collapsible mast upwardly, the weight of the boom thus causing the cables 33 to be taut. The struts 23 maintain the collapsible mast 22 at its intended oblique elevation against tendency of the weight of the boom to swing said collapsible mastv upwardly and forwardly. In said Fig. l, the upper and lower telescopic rods 54 and 55 of the struts 23 have their greatest length, the collar members 58 on the lower rods 55 being engaged against the cap members 51 on the upper rods 54.

When it is desired to` collapse the mast 22 and remove the counterweight 52, operations as hereinafter set forth will be accomplished. The boom. cable 46 will be tightened suiciently, in response to operation of the rotatable drum 45 while the hoist hook 49 is attached, as by a chain 6|, to a tow lug 62 upon the front of the truck body I6 and the hoisting hook cable 50 is xedly held by the rotatable drum 48, to cause the counterweight 52 to be supported or suspended. Or, the hoisting hook cable 50 may be shortened while the hoisting hook is attached to the tow lug and the boom cable 46 is fixedly held by the rotatable drum 45 to cause the weight of said counterweight to be supported or suspended. See Fig. 1. While said counterweight is thus supported or suspended, the bolts 53 can be removed thus to release the counterweight from the rotatable platform. Then said counterweight will be lowered by gravity to the ground, as in Fig. 2, by paying out one of the cables, 46 or 50, of course in response to operation of the corresponding rotatable drum, and, while the counterweight is rested upon the ground and the struts 23 are yet secured to said counterweight, the boom will be lowered into a cradle 63 of the crane, by paying out the boom cable 46, as` in Fig. 3. After the counterweight is released from the struts 23, while the boom 20 is situated in the cradle 63, the lower ends of the lower telescopic rods 55 will be secured, as at 64, to the rear of the rotatable platform I8, or part of said rotatable platform opposite the boom 20 and its pivotal support 2|. The upper and lower telescopic rods 54 and 55 of the struts 23 are capable of sufficient relative movement to permit the collapsible mast 22 to be horizontally disposed, as in Fig. 4J when said lower telescopic rods are secured to the rotatable platform, and when said collapsible mast 22 is horizontal, by reason of sucient payout of the boom cable 46, the cross pin 4| and the transverse shaft 29 will be in adjacent relation and substantially vertical alinement, with said cross pin situated above said transverse shaft in position to be detachably secured thereto. In Fig. 11, the cross pin 4| which pivotally connects the spaced ears 42, rigid with the transverse members 43 to the adjacent ends of the spaced bars 24, has been assembled with annular links 65 slidably disposed upon the transverse shaft 29 thus to pivotally connect said spaced ears and transverse shaft to each other. As shown, the annular links 65 have openings 66 which receive opposite end portions of the cross pin 4|. Cotter pins 6l retain said cross pin in its intended position.

In Figs. 4 and 11 of the drawings, where the spaced ears 42, rigid with the transverse plate members 43, are pivotally connected to the transverse shaft 29, the unit consisting of the collapsible mast 22, the struts 23 and the bars 24 is inoperative. Instead, suspension of the boom through the instrumentality of the cable 46 is directly from the transverse shaft 29 and the cross pin 4| upon which the transverse plate members 43 and the spaced ears 42 are pivotally r supported. With the boom suspended as in said Fig. 4, the counterweight 52 can be lifted from the ground and placed upon a conveying vehicle therefor, as suggested in Fig. 5 of the draw--V ings. The crane is set up in said Fig. 5 to be operative independently of the collapsible mast 22.

In Fig. 6 of the drawings, the crane is disclosed as when its` operative parts have been moved or adjusted back to their positions about as in Fig. 4 from operative positions as in Fig. 5. In Figs. 4 and 6 the crane is set up as when ready for transportation under its own power, or for shipment under the power of a different vehicle,

with the mast 22 collapsed and the counterweight 52 removed.

To again situate the mast 22 at its oblique position and suspend the counterweight 52 upon the revolvable platform I8, as in Figs. I1 and 12 of the drawings, it is only necessary to perform operations which are the reverse of those employed to collapse said mast and remove said counterweight.

What is claimed is:

l. In a machine of the character described, a supporting structure, a boom pivotally mounted upon said supporting structure, a pair of upright spaced struts at the rear of said supporting structure each constituted as an upper and a lower telescopic rod, means securing a lower end of the lower rod of each of said spaced struts upon said supporting structure, a first transverse shaft mounted upon an upper end of the upper rod of each of said spaced struts, spaced apart, upstanding arms upon said supporting structure at a location forwardly of said spaced struts and rearwardly of said boom, a second transverse shaft mounted upon an upper end of each of said upstanding arms, a mast having a lower, forward end thereof pivotally mounted upon said second transverse shaft and an upper, rearward end thereof pivotally mounted upon said vfirst transverse shaft, said mast normally slanting upwardly obliqely away from its pivotal support upon said second transverse shaft and away from said boom, a boom suspension constituted as an elongated member having a rearward end thereof pivotally mounted upon said first transverse shaft, a cross pin mounted in spaced elements at the forward end of said elongated member and a cable extending between sheaves supported upon said cross pin and an outer portion of said boom for supporting the boom from the mast when in normal upwardly slanting position, means for limiting the extent to which the upper rodsof said spaced struts can be moved outwardly of the lower rods thereof thus to maintain the mast at fixed oblique elevation against tendency of the weight ofthe boom when suspended4 from the mast toward causing said mast to be swung upwardly toward said boom, the boom being releasable from supported relation to the mast by lengthening of said cable and said mast and said elongated member with said cross pin being movable to lowered position upon release of said boom, and means for detachably securing said cross pin to an intermediate portion of said second transverse shaft at a side thereof.

2. The combination as specified in claim 1 wherein the lower ends of the lower rods of said spaced struts are detachably secured to a counterweight itself detachably secured to said supporting structure.

References Cited in the le of this patent UNITED STATES PATENTS:

Number Name Date 1,560,194 Armstrong Nov. 3, 1925 2,130,487 Foley Sept. 20, 1938 2,325,089 Zeilman July 27, 1943 2,348,285 Ekbom et al May 9, 1944 2,382,767 Zeilman Aug. 14, 1945 2,411,305 Taylor et al Nov.. 19, 1946 

